The team led by Prof. Johann Kollegger at the Institute of Structural Engineering at TU Wien has developed a new tower-construction method which combines the key benefits of the existing methods. Double-wall elements are initially joined together on the ground to form large double-walled concrete rings. These rings are then lifted one on top of the other and finally filled with concrete. The construction of tall wind turbine towers is said to be faster and less expensive using this technique.
Prof. Kollegger explains: “In wind turbine construction, large precast concrete parts are usually delivered to the construction site. These are then assembled into a tower and then fixed to one another. This method is quite fast, but the costs associated with the special transportation of large precast parts can often be high.” In addition, the tower construction method developed by TU Wien also features thinner walls and less reinforcing steel which means using significantly fewer resources compared to familiar precast construction methods.
In recent years, Kollegger’s team has repeatedly created a stir with their new and creative concrete construction solutions, for instance with a folding bridge or even a concrete dome, which can be formed by inflating an air cushion beneath the concrete. And now a new concrete tower construction method has been successfully tested.
Instead of heavy, solid concrete rings, hollow, rectangular double-walled elements are transported to the construction site. These double-walled elements are erected and joined together in a circle, so that they form a polygonal segment with outer and inner walls. “The segments are then stacked on top of one another, retaining the hollow space between the two walls,” says Kollegger. “Only then is the inner space filled with concrete – one segment at a time.” A monolithic concrete block is created, whereby the segments are joined together in an extremely stable way.